The phylum Echinodermata is a taxonomic group that includes sea stars, sea urchins, and sea cucumbers. The word "Echinodermata" is spelled using the International Phonetic Alphabet (IPA) as /ɛkɪnoʊˈdɜrmətə/. The first two syllables, "eko" and "no", are pronounced with a short "e" sound as in "bet". The "d" in "derm" is pronounced as a "j" sound like "jerm" and "a" is pronounced as "uh". The stress falls on the third syllable, "derma".
Phylum Echinodermata refers to a major taxonomic group comprising marine invertebrates characterized by their spiny skin, radial symmetry, and water vascular system. It is one of the largest animal phyla, including about 7,000 known species. The name "Echinodermata" is derived from the Greek words "echinos" meaning "hedgehog" and "derma" meaning "skin," describing their characteristic spiky or prickly appearance.
Members of the phylum Echinodermata include diverse organisms such as sea stars, sea urchins, sea cucumbers, brittle stars, and crinoids. While they exhibit radial symmetry as adults, they typically develop from bilaterally symmetric larvae. The most distinctive feature of echinoderms is their water vascular system, a network of fluid-filled canals that enables them to perform various functions such as locomotion, respiration, and feeding. This system is operated by muscular contractions and regulates the movement of thousands of tiny tube feet found on their undersides.
Echinoderms also possess a unique endoskeleton made up of calcified plates or ossicles, which provide support and protection. Their spiny and sometimes leathery skin serves as a protective barrier. They have a decentralized nervous system with sensory cells dispersed throughout their bodies, allowing them to respond to various stimuli.
Phylum Echinodermata exhibits a wide range of ecological roles and adaptations. They inhabit diverse marine environments, from shallow coastal areas to ocean depths. They play key roles in marine ecosystems, serving as predators, scavengers, and filter feeders. Some species also have remarkable regenerative abilities, being capable of regrowing lost limbs or even whole bodies.
Due to their unique characteristics and ecological importance
The word "Phylum Echinodermata" comes from the Greek roots "echinos" meaning "spiny" and "derma" meaning "skin". The term was coined by the British scientist Richard Owen in 1835 to describe a group of marine animals characterized by their spiny skin. Echinodermata is a taxonomic phylum that includes organisms such as sea stars, sea urchins, and sand dollars.